1/*
2 * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
3 * All rights reserved.
4 *
5 * This source code is licensed under both the BSD-style license (found in the
6 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
7 * in the COPYING file in the root directory of this source tree).
8 * You may select, at your option, one of the above-listed licenses.
9 */
10
11#ifndef ZSTDv07_H_235446
12#define ZSTDv07_H_235446
13
14#if defined (__cplusplus)
15extern "C" {
16#endif
17
18/*====== Dependency ======*/
19#include <stddef.h> /* size_t */
20
21
22/*====== Export for Windows ======*/
23/*!
24* ZSTDv07_DLL_EXPORT :
25* Enable exporting of functions when building a Windows DLL
26*/
27#if defined(_WIN32) && defined(ZSTDv07_DLL_EXPORT) && (ZSTDv07_DLL_EXPORT==1)
28# define ZSTDLIBv07_API __declspec(dllexport)
29#else
30# define ZSTDLIBv07_API
31#endif
32
33
34/* *************************************
35* Simple API
36***************************************/
37/*! ZSTDv07_getDecompressedSize() :
38* @return : decompressed size if known, 0 otherwise.
39 note 1 : if `0`, follow up with ZSTDv07_getFrameParams() to know precise failure cause.
40 note 2 : decompressed size could be wrong or intentionally modified !
41 always ensure results fit within application's authorized limits */
42unsigned long long ZSTDv07_getDecompressedSize(const void* src, size_t srcSize);
43
44/*! ZSTDv07_decompress() :
45 `compressedSize` : must be _exact_ size of compressed input, otherwise decompression will fail.
46 `dstCapacity` must be equal or larger than originalSize.
47 @return : the number of bytes decompressed into `dst` (<= `dstCapacity`),
48 or an errorCode if it fails (which can be tested using ZSTDv07_isError()) */
49ZSTDLIBv07_API size_t ZSTDv07_decompress( void* dst, size_t dstCapacity,
50 const void* src, size_t compressedSize);
51
52/**
53ZSTDv07_getFrameSrcSize() : get the source length of a ZSTD frame
54 compressedSize : The size of the 'src' buffer, at least as large as the frame pointed to by 'src'
55 return : the number of bytes that would be read to decompress this frame
56 or an errorCode if it fails (which can be tested using ZSTDv07_isError())
57*/
58size_t ZSTDv07_findFrameCompressedSize(const void* src, size_t compressedSize);
59
60/*====== Helper functions ======*/
61ZSTDLIBv07_API unsigned ZSTDv07_isError(size_t code); /*!< tells if a `size_t` function result is an error code */
62ZSTDLIBv07_API const char* ZSTDv07_getErrorName(size_t code); /*!< provides readable string from an error code */
63
64
65/*-*************************************
66* Explicit memory management
67***************************************/
68/** Decompression context */
69typedef struct ZSTDv07_DCtx_s ZSTDv07_DCtx;
70ZSTDLIBv07_API ZSTDv07_DCtx* ZSTDv07_createDCtx(void);
71ZSTDLIBv07_API size_t ZSTDv07_freeDCtx(ZSTDv07_DCtx* dctx); /*!< @return : errorCode */
72
73/** ZSTDv07_decompressDCtx() :
74* Same as ZSTDv07_decompress(), requires an allocated ZSTDv07_DCtx (see ZSTDv07_createDCtx()) */
75ZSTDLIBv07_API size_t ZSTDv07_decompressDCtx(ZSTDv07_DCtx* ctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
76
77
78/*-************************
79* Simple dictionary API
80***************************/
81/*! ZSTDv07_decompress_usingDict() :
82* Decompression using a pre-defined Dictionary content (see dictBuilder).
83* Dictionary must be identical to the one used during compression.
84* Note : This function load the dictionary, resulting in a significant startup time */
85ZSTDLIBv07_API size_t ZSTDv07_decompress_usingDict(ZSTDv07_DCtx* dctx,
86 void* dst, size_t dstCapacity,
87 const void* src, size_t srcSize,
88 const void* dict,size_t dictSize);
89
90
91/*-**************************
92* Advanced Dictionary API
93****************************/
94/*! ZSTDv07_createDDict() :
95* Create a digested dictionary, ready to start decompression operation without startup delay.
96* `dict` can be released after creation */
97typedef struct ZSTDv07_DDict_s ZSTDv07_DDict;
98ZSTDLIBv07_API ZSTDv07_DDict* ZSTDv07_createDDict(const void* dict, size_t dictSize);
99ZSTDLIBv07_API size_t ZSTDv07_freeDDict(ZSTDv07_DDict* ddict);
100
101/*! ZSTDv07_decompress_usingDDict() :
102* Decompression using a pre-digested Dictionary
103* Faster startup than ZSTDv07_decompress_usingDict(), recommended when same dictionary is used multiple times. */
104ZSTDLIBv07_API size_t ZSTDv07_decompress_usingDDict(ZSTDv07_DCtx* dctx,
105 void* dst, size_t dstCapacity,
106 const void* src, size_t srcSize,
107 const ZSTDv07_DDict* ddict);
108
109typedef struct {
110 unsigned long long frameContentSize;
111 unsigned windowSize;
112 unsigned dictID;
113 unsigned checksumFlag;
114} ZSTDv07_frameParams;
115
116ZSTDLIBv07_API size_t ZSTDv07_getFrameParams(ZSTDv07_frameParams* fparamsPtr, const void* src, size_t srcSize); /**< doesn't consume input */
117
118
119
120
121/* *************************************
122* Streaming functions
123***************************************/
124typedef struct ZBUFFv07_DCtx_s ZBUFFv07_DCtx;
125ZSTDLIBv07_API ZBUFFv07_DCtx* ZBUFFv07_createDCtx(void);
126ZSTDLIBv07_API size_t ZBUFFv07_freeDCtx(ZBUFFv07_DCtx* dctx);
127
128ZSTDLIBv07_API size_t ZBUFFv07_decompressInit(ZBUFFv07_DCtx* dctx);
129ZSTDLIBv07_API size_t ZBUFFv07_decompressInitDictionary(ZBUFFv07_DCtx* dctx, const void* dict, size_t dictSize);
130
131ZSTDLIBv07_API size_t ZBUFFv07_decompressContinue(ZBUFFv07_DCtx* dctx,
132 void* dst, size_t* dstCapacityPtr,
133 const void* src, size_t* srcSizePtr);
134
135/*-***************************************************************************
136* Streaming decompression howto
137*
138* A ZBUFFv07_DCtx object is required to track streaming operations.
139* Use ZBUFFv07_createDCtx() and ZBUFFv07_freeDCtx() to create/release resources.
140* Use ZBUFFv07_decompressInit() to start a new decompression operation,
141* or ZBUFFv07_decompressInitDictionary() if decompression requires a dictionary.
142* Note that ZBUFFv07_DCtx objects can be re-init multiple times.
143*
144* Use ZBUFFv07_decompressContinue() repetitively to consume your input.
145* *srcSizePtr and *dstCapacityPtr can be any size.
146* The function will report how many bytes were read or written by modifying *srcSizePtr and *dstCapacityPtr.
147* Note that it may not consume the entire input, in which case it's up to the caller to present remaining input again.
148* The content of `dst` will be overwritten (up to *dstCapacityPtr) at each function call, so save its content if it matters, or change `dst`.
149* @return : a hint to preferred nb of bytes to use as input for next function call (it's only a hint, to help latency),
150* or 0 when a frame is completely decoded,
151* or an error code, which can be tested using ZBUFFv07_isError().
152*
153* Hint : recommended buffer sizes (not compulsory) : ZBUFFv07_recommendedDInSize() and ZBUFFv07_recommendedDOutSize()
154* output : ZBUFFv07_recommendedDOutSize== 128 KB block size is the internal unit, it ensures it's always possible to write a full block when decoded.
155* input : ZBUFFv07_recommendedDInSize == 128KB + 3;
156* just follow indications from ZBUFFv07_decompressContinue() to minimize latency. It should always be <= 128 KB + 3 .
157* *******************************************************************************/
158
159
160/* *************************************
161* Tool functions
162***************************************/
163ZSTDLIBv07_API unsigned ZBUFFv07_isError(size_t errorCode);
164ZSTDLIBv07_API const char* ZBUFFv07_getErrorName(size_t errorCode);
165
166/** Functions below provide recommended buffer sizes for Compression or Decompression operations.
167* These sizes are just hints, they tend to offer better latency */
168ZSTDLIBv07_API size_t ZBUFFv07_recommendedDInSize(void);
169ZSTDLIBv07_API size_t ZBUFFv07_recommendedDOutSize(void);
170
171
172/*-*************************************
173* Constants
174***************************************/
175#define ZSTDv07_MAGICNUMBER 0xFD2FB527 /* v0.7 */
176
177
178#if defined (__cplusplus)
179}
180#endif
181
182#endif /* ZSTDv07_H_235446 */
183